Experimental assessment of plant seed retention times in fur of cattle and horse

Abstract

Epizoochorous dispersal of plant seeds is an important long-distance dispersal mechanism. Yet little is known about retention times of seeds in animal furs and hence about potential dispersal distances of the seeds. Here, we used marked seeds of 12 plant species to determine seed depletion curves on Galloway cattle and Haflinger horse in three vegetation types (forest, tall herbage vegetation and meadow), in both dry and rainy weather conditions. In the long fur of Galloway cattle, seeds were retained significantly longer than in the short fur of Haflinger horse. In general, seed retention times were not considerably affected by the structure of the surrounding vegetation. The impact of the weather was negligible, only affecting the retention of some plant species. Negative exponential functions were fitted to the seed depletion curves. Using the parameters of curve estimations in the different conditions of animal species and vegetation structure, half-life seed retention times of up to 13 h for Galloway cattle and up to more than 4 h for Haflinger horse could be calculated, with corresponding potential half-life dispersal distances in the order of magnitude of tens of metres to a few kilometres. Different seed traits correlated with seed retention times in the long cattle fur and in the short horse fur, respectively.